Jack-arm.



PATENTED JAN.1'7, 1905. S. L. G. KNOX.

JACK ARM.

APPLIUATION FILED MAY 2s. 1904.

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No. 780,201. PATENTED JAN. 17. 1905. S. L. G. KNOX.

JACK ARM.

APPLIUATION HLED MAY 23. 1904.

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IINTTED STATES Patented January 1 7, l 905.

PATENT OEEICE.

SAMUEL LIPPINCOTT GRISWOLD KNOX, OF MILWAUKEE, WISCONSIN, ASSIGNOR TO BUCYRUS COMPANY, OF SOUTH MILWAUKEE, VIS- CONSIN, A CORPORATION OF WISCONSIN.

JACK-AFIN!- SPEGIFICATION forming part of Letters Patent No. 780,201, dated January 1.7, 1905.

Application led May 23, 1904. Serial No. 209,296.

To raf/ZZ when?, t may concern.-

Beit known that I, SAMUEL Lirrmcorr GRIswoLD KNOX, a citizen of the United States, residing in the city and county of Milwaukee, State of Wisconsin, have invented certain new and useful Improvements in Jack- Arms; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

The purpose of my invention is to provide a jack-arm for railway wrecking-cranes, excavators, and the like that is adapted to be applied to the car as a permanent part of the equipment and that shall combine'the requi site strength and stability under the heaviest loads with a relative lightness and simplicity of structure so related to the car-body that the said jack-arm may be easily and quickly handled and adjusted, that it may have astable balance for both its eXtreme positions, that it shall not render a material reduction of the maximum width of the car-body with regard to railway clearance necessary, and that is readily removable from the car-body should removal be found necessary, due to an abnormally low clearance or to any other unusual working conditions on the road.

To this end the invention comprises a jackarm having two divergent legs, preferably formed as an integral V-shaped casting pivoted at one end to the car-body to swing in a vertical plane, the free end of the other leg finding a bearing to take the lateral thrust in an abutment on the ear-body, and a strut pivoted to the car-body and connected to the jack-arm to stiffen the latter in a direction normal to its swinging plane, together with means, preferably in the form of a helical spring', interposed between the inboard end of the jackarm and the ear-body to counterbalance the free end of the arm and hold said arm in its inner and outer positions.

Referring to the accompanying drawings, Figure l Vis a side elevation of my improved jack-arm applied to the side of a car-body,

near one cornerthereof. Fig. 2 is an end elevation thereof.

In the drawings, (a indicates the main leg of the jaclearm, from which projects a lateral leg having' at the point of juncture which constitutes the free end of the jack-arm a bearing-surface c, under which the blocking or other supporting' means is applied. The legs d and are preferably formed as an integral V-shaped casting provided with a fork or clevis (Z at the upper end of the main leg, by which the jack-arm is journaled on a removable pintle v1, carried by a lug /L on the side of the car-body, so that said arm swings in a vertical plane, preferably normal to the side of the car. The pintle is held in position in the lug /L by a set-screw j, which may be quickly removed to allow the pintle to be withdrawn.

The lateral leg 7) is so disposed as to swing in the same plane as leg a, and movement of the inner end of said leg is preferably conlined to a path inclosed within the frame of the car-body side A and end B. Secured in the inner end of leg L is a pin g, which projects laterally on both sides of said leg and is adapted to engage semicircular recesses c in abutment-plates C C, secured within the car-body when the jack-arm is swung to its outward or operative position, as shown in Fig. l, so that the movement of the arm is properly limited by said abutment, and the latter takes up the lateral thrust on the arm dueto the load.

In order to stiften the jack-arm in a direction normal to its swinging plane and to prevent undue lateral strain on the pintle/1I, a

brace or strut is pivoted to the car-body at one end and connected to the lower end of the jack-arm at the other, so that Said strut partakes of the vertical-swinging movement of said arm. The pivot f', by which the strut is connected to the car-body, is mounted in brackets a a, so that the axis of said pivot v7 coincideswith that of pintle/I. The otherend of the strut engages a socket g in the lower end of the leg (t and is secured thereto by a cross pin or bolt p. The strut and the jackarm are thus rigidly connected and swing as a unitary structure throughout the range of movement of said arm, and any tendency of the arm to yield laterally of its swinging plane is effectively resisted.

The two positions of the jack-arm. which characterize its operative adjustment in supporting' a load and its folded or retracted relation with respect to the car-body during transportation, are indicated in the full and dotted lines, respectively, in Fig. l. It is desirable that the jack-arm be retained in either of these positions without the interposition of extraneous auxiliary support. More especially should the arm be automatically counterbalanced in its outer or operative position, so that once it has been adjusted the blocking` or other supporting means can be applied beneath the bearing face c without requiring the arm to be held in position by the workmen. This counterbalancing 'of the arm is accomplished in the present instance by means of a helical spring fr, which bears at one end against an abutment on the car-body and against a cross-pin o on the inner end of leg at the other end. Said spring being under compression at all times produces a thrust against said arm, and in order to deliver the thrust in a direction to hold the jack-arm in both of its eXtreme positions the pin a' is mounted on the car-body at a point so that in the operative position of the jack-arm the angle formed by the center line through spring fr and a line through pivot c' and pin r is approximately equal to the angle formed by the center line and the line connecting pivot and pin .r when the jack-arm is in its folded position, and the strength of the spring is preferably so adjusted as to counteract the turning movement of said jack-arm about its pivot at t, due to the weight of the arm. It will be seen also that one effect of the spring is to assist in the movement of the arm in either direction beyond its middle position.

The spring-counterbalance device consists of the helical spring fr, above referred to, which is'mounted upon a guide formed as a U-shaped frame S, secured by a bolt fw to a cap z5, which is provided with a fork or yoke engaging pin r on leg A washer u, slidably mounted on frame S, abuts against pin a; on the car-body and serves to hold the spring against the cap 2f as the .frame is reciprocated on pin ai asaguide. As thejaclr-arm is swung from its eXtreme positions the spring fr is compressed during the first half of the movement and the frame S is moved forward on pin and during the latter half of the arms movement the spring expands and assists in moving the arm and iinally retains it in its ultimate position with force suflcient to counterbalance the weight of the arm.

To 'prevent swinging of the jack-arm from its folded position during transportation, leg a is provided with a lug f on its rear side, which lug registers with a pair of lugs y y on the car-body, and a pin e, passed through the orifices inlug'sf and y, serves to lock the jackarm to the car-body.

Having thus described my invention, what I claim is- 1. A jack-arm for railway-cars, comprising a main leg pivoted to the car-body and swinging in a vertical plane, a lateral leg connected to said main leg, and an abutment on the car engaging said lateral leg in the outer position of the jack-arm to take up the lateral thrust of said arm.

2. A jack-arm for railway-cars, comprising a V-shaped member pivoted at one end to the car-body to swing in a vertical plane, and an abutment on the car engaging the other end of the V-shaped member to limit the outward movement of said arm and take up the lateral thrust thereof.

3. A jack-arm for railway-cars, comprising a main leg pivoted to the car-body and swinging in a vertical plane, a lateral leg connected to said main leg, an abutment on the car engaging said lateral leg in the outer position oi' the jack-arm to take up the lateral thrust of said arm, and a strut connected to the lower portion of the arm at one end and to the carbody at the other end to stiften said arm in a direction normal to its swinging plane.

4. A jack-arm for railway-cars, comprising a V-shaped member pivoted at one end to the car-body to swing in a vertical plane, an abutment on the car engaging the other end of the V-shaped member to limit the outward movement of said arm and take up the lateral thrust thereof, and a strut connected at one end to the lower portion of the V -shaped member and pivoted to the car-body at the other end to stiifen said jack-arm in a direction normal to its swinging plane.

5. A jack-arm for railway-cars, comprising two angularly-disposed legs having a bearingface at the point of juncture, a pivotal support on the car-body for the free end of one of said legs to permit said legs to swing in a vertical plane, and an abutment on the ca'r in the path of movement of the free end of the other leg to limit the outward movement of said legs and take up the lateral thrust thereof.

6. A jack-arm for railway-cars, comprising a V-shaped member pivoted at one end to the car-body to swing in a vertical plane, an abutment on the car engaging the other end of said V-shaped member at the limit of its outer movement, and means connected to the latter'- mentioned end of the V-shaped member and the car-body, respectively, to counterbalance the free end of the jack-arm and hold the jackarm in its inner and outer positions.

7. A jack-arm for railway-cars, comprising IOO IIO

e tif-shaped member pivoted at one end to the car-body to swing in a vertical plane, an abutment on the car engaging the other end of seid Wsheped member :it the limit of its outer movement, and a spring connected to the letter-mentioned end oi'l the V-shaped member and the ear-body, respectively, to counterbelzmce the free end of the jeclverm and hold the jack-erm in its inner and outer positions.

r 8. A jack-erm for railway-cars, comprising' e W-sheped member pivoted at one end to the car-body to swing in e vertical plane, an abutment on the car engaging the other end of said tI-shaped member et the limit of its outer movement, a spring connected to the lattermentioned end of the il-shaped member end the eer-body respectively, to counterbalance the free end of the jack-arm and hold the jackarm in its inner and outer positions, and e' strut connected et one end to the lower portion oil the il-shaped member and pivoted to the car-body at the other end to stiften said jack-arm in a direction normal to its swing'- ing plane.

9. A jack-erm for railway-ears, comprising e tl-shaped member pivoted by one leg to the car-body and swinging in a vertical plane, the other leg extending' inside of the ear-body, and means for limiting' the outward movement of said jack-arm.

ein

10. A jack-erm for reilwztybers, comprising a V-sheped member pivoted by one leg to the Y -ing and to the eer-body to counterbalmice the free end oi' the jack-arm and hold the letter in its inner and outer positions.

l2. A jecleerm for rail wey-cars, comprising' a V-sheped casting pivoted et its outer end to the car-body and swinging in a vertical plane, en abutment on the car-body engaging the in ner end of seid casting to limit the outward movement of the erm, and a helical spring connected to the said inner end amd to the earbody at a point in line with the middle position of the inner end and the pivot, to counterbelence the free end of the jack-arm.

In testimony whereoi'l I eilix my signature in presence of two witnesses.

SAMUEL LI'PPNCOTT GRISWOLD KNOX. fitness es:

PAUL C. Bonn, HARRY B. HAYDEN. 

